The proposed research attempts to achieve a comprehensive understanding of the cognitive social psychological factors in adolescent cigarette smoking. A longitudinal study will examine the psychological processes underlying the important periods of transition from nonsmoker to smoker. Two major social psychological theories (Ajzen and Fishbein's model for the prediction of behavioral intentions and Jessor and Jessor's Problem Behavior Theory) will be used to predict such transitions. We will also identify "high risk" variables for smoking transitions by comparing the presmoking data for subjects who begin to smoke over the course of the study with the data for subjects who do not begin to smoke. Furthermore, by examining "high risk" adolescents who do not begin to smoke, we can identify variables that serve as deterrents to smoking. We will examine adolescents' belief systems to determine which types of attitudes and beliefs are most relevent to smoking decisions. Several cross-sectional studies supplement the major longitudinal approach. We will study characteristics that are attributed to smokers in a variety of contexts. Evaluations of smokers and nonsmokers in these contexts should help us discover some of the functions that smoking serves for adolescents. Our results will have direct applications to guide the content of antismoking programs as well as to identify the most appropriate target groups for such campaigns.